UPDATE - callback itself is working now. If user is meant to be called back - it is called back succesfuly. Problems are with users who should not be called back - normal dial-in users - if 'ppp callback accept' is configured on group-async interface - problem arise, if that command isnt there - non-callback users can call in, but callback isnt working.

If I try to call-in as non-callback user, Windows says that "PPP Link Control Protocol was terminated by remote side" and it says that I should enable LCP extensions (its done and ON by default also) and try to allow unsecured password (what is also allowed).

I'm trying to configure callback from 3640 (E1) to WindowsXP PC (async line). There are several types of users callin to that NAS - Cisco routers using ISDN, async modem users who shouldnt be called back, and now there should be async modem users who should be called back. This is why I need per user AAA what is done using RADIUS. Below is RADIUS profile configuration.

NAS (3640) has numerous mica-midems installed. Dial-in without callback is working fine, as AAA is done using RADIUS server, so configuration for vaccess interfaces comes also from vtemplate + RADIUS part.

What I'm worried about is command "ppp callback accept". As far as I know - it should be configured on group-async interface, but if I do it - nobody is able to call-in in any manner (with callback or without). "debug aaa authentication" says that user isn't authorized for callback and AAA procedure exits at that moment (or maybe I'm not doin enough debugging, so Im missin something).

Any ideas how to proceed and what to troubleshoot? Maybe anyone has got working configuration for callback? Any ideas what to debug? I understand that there might be not enough information, if you need something else to give some comments - I'll do it :-)